Finding the Fourth Proportional to 111.78, 168.48 and 92.88

Step by Step Solution

1. Step 1: Write the proportion equation
   111.78 : 168.48 = 92.88 : x
2. Step 2: Convert to fraction form
   111.78/168.48 = 92.88/x
3. Step 3: Cross multiply
   111.78x = 168.48 × 92.88
4. Step 4: Simplify right side
   111.78x = 15,648.42
5. Step 5: Solve for x
   x = 15,648.42/111.78
6. Step 6: Final answer
   x = 139.99